Problems with 87 TR....HELP!!!!!

No trouble Al, glad to help out. There's no reason to remove the coolant temp thermister to remeasure the resistances -- if it measures properly when it's mounted in-place that's what you want.

As I said before, no need to look at the thermo-time switch for your problem yet. The attached jpeg shows how the internals are wired for your version. I don't know the nominal values for the resistances R1 and R2. The body of the switch is connected to ground, and the little set of contact points shown to the right of R2 will be closed when cold and open when warm.

I'm not thinking about what to do next until you measure the red wire .
Image Unavailable, Please Login

 

At least that gives you something to "fix" and see/hope if it solves the problem

There are four problems that you could have:

1. No +12V power to the "C" relay socket on the 30 terminal,
2. No ground connection at the "C" relay socket on the 31 terminal,
3. No +12V on the wire coming into the 15 terminal of the "C" relay from the tachometric relay when cranking/running, or
4. A bad "C" relay

The easiest thing to try is to remove the relay "C" (the one with the 10 amp fuse) from its socket and measure the voltage from the 30 terminal of the relay socket to ground. If it measures +12V, make up a jumper wire to connect the 30 terminal of the socket to the 87 terminal of the socket and try starting/running the engine and remeasuring what happens at the red wire (and see how the engine runs).

The way relay "C" works is:

30 terminal = +12V relative to ground all the time (this is a direct line from the battery so it's always hot)

31 terminal = ground (when you have the "C" relay removed make a resistance measurement from this terminal to another ground location -- should be low -- a few ohms maximum.)

15 terminal = should be +12V whenever the starter motor is cranking or the engine is running (if you do the "jumping" from 30-to-87 described above and the engine runs well, measure this 15 wire terminal to confirm/deny the +12V presence),

87 terminal = the red wire -- should be +12V when the signal conditions listed for terminals 30, 31, and 15 above are met (when the relay "C" is plugged in).

If you confirm the signal conditions for terminals 30, 31, and 15 are all OK, but terminal 87 (and the red wire) isn't at +12V (when you've got the relay "C" plugged in), this confirms that the relay "C" is bad.

Confirm/deny/try these things, and we should be able to figure out the fix or what to do next.

PS That diagram is for your thermo-time switch -- but that's not part, or a cause, of your problem!

 

16 gauge or larger wire would be fine. If you can put a 10A fuse in the jumper wire that would be great (but since your 10A fuse on the C relay wasn't blown, I don't think there's any big risk just using a plain wire for the jumper).

 

Relay C is a fairly specialized odd-ball relay IMO (I can't recall if it's a Bosch or Streibel or ?). Anyone who regularly sells F parts for the K/KE-Jet F models(Ricambi America, FerrariUK, Rutland, etc.) would probably be able to supply it (but not a typical domestic Auto Parts Store IME).

But don't go there yet -- if there's something wrong in the Tachometric system (i.e., no +12V on terminal 15 at Relay C during cranking/running), Relay C could be perfectly OK, and it's just not getting the input signals that it needs.

If you mention the thermo-time switch one more time, I'm going to get on a jet and come whip your a** That red wire +12V power network is so critical to KE system function that worrying about the thermo-time switch is like worrying about a scratch on your arm after a shark's taken your leg off. If you want to test the thermo-time switch system, put your 12V incandesant test lamp from the orange wire in the "j" connector to ground. The bulb should come on for a second or two during initial starter cold-cranking, and it would flash if you blipped the acc. pedal during the cold-running period (water temp lests than about 150 deg F IIRC) IF the red wire +12V power network was healthy (so yours won't do this correctly as-is). The jpeg shows the white connectors at the bottom of fuse/relay panel as facing them from the front.
Image Unavailable, Please Login

 

Al -- Well done so far (and thank you for not mentioning the T-T switch ). No +12V power on that red wire network in a KE is a killer because, when missing, there's no current flowing in the EM valves on the fuel distributors (so they start working like very mis-tuned K-Jets).

With relay "C" removed, and using the 30-87 jumper wire, get the engine running again and measure the voltage on the wire coming into the 15 terminal of the relay C socket:

If +12V is present, buy a new relay "C"

If no voltage is present, you have a problem further upstream in the Tachometric system.

PS With regard to the C12 and C13 connectors (using the US version terms), I did the Aluminum parts when I thought replacement rings were "unobtanium" (so cost and hassle were no object). I later learned that AMP still makes similar versions of those same connectors so you can just swap over a ring removed from the new connector. See this thread for part numbers/sources:
http://ferrarichat.com/forum/showthread.php?t=37351

 

Great thread you guys. Going to print it and put in maint man. Thanks. SS

 

Al -- I think I've got the Manufacturer Name & PN for my relay "C" in my notes(and it definitely has a 10A fuse built-in as shown on the TR wiring schematics). Porsche & F both produced models with Bosch CIS injection so having similar "protection relays" seems very possible to me, but there might be slightly different flavors. I'll post what information I have in a few hours.

I think your "worst nightmare" right now is probably buying a new relay "C" (since your fuel pumps seem to be working and they also depend on the +12V coming from the Tachometric relay system for operation), but make the terminal 15 measurement to confirm things before buying a new one.

With regard to hooking up the red and orange/black wires to the water temp switch -- doesn't matter, either way is OK. Both terminals are just one contact side of the isolated switch built inside the water temp switch body.

 

Very little, but it is still possible (although remote) that you have a wiring harness defect and that the +12V from the Tachometric relay is just not reaching the relay C terminal 15 (even though that same +12V signal from the Tachometric relay does reach the fuel pump relays and closes them to run the fuel pumps). I like to measure and know all things before buying expensive electrical gizmos -- just to be sure.

As you say, the 10A fuse is actually "external" to the relay C's box -- by "built-in" I just meant that it was/is attached to the relay itself.

I thought I had written down the actual data from my TR's relay C, but I can't find it now. The TR 587/90 SPC says relay C is:

Ferrari PN 61766200
Manufacturer: Stribel
Manf. PN: 928.615.124.00

is yours the same?

When you add the jumper between terminal 30 and 87 you're simulating a "closed" relay C (and it's natural for one of the other Bosch relays in that area to also "click" when relay C closes). To "test" relay C, it's as I described before:

with terminal 31 at ground
and terminal 15 at +12V
terminal 30 should be connected to terminal 87

This is why if you confirm that things are OK at terminals 31 and 15 and measure +12V at terminal 30, but not +12V at terminal 87 (which is connected to the red wire at the water temp switch) this confirms relay C is toast. Alternatively, if you have the relay on the bench and you put +12V on terminal 15 and ground on terminal 31, the resistance measured from terminal 30 to terminal 87 should be low (i.e., a few ohms maximum).

 

Having the identical Manf. PN is a good sign IMO, and would indicate to me that it probably is a proper equivalent relay to the Stribel -- just from a different Germany-based manufacturer.

The +12V from the Tachometric relay takes different physical paths to the fuel pump relays and to relay C -- so if the physical path to relay C is bad, the physical path to the fuel pump relays can still be OK. If you don't have +12V on terminal 15 when running then you would have to start looking at the connection path from the Tachometric relay to relay C, but it's 90% probable that your relay C is toast.

Jumping terminal 30-to-87 has no effect on what is, or isn't, happening at terminal 15.

And, yes, a high resistance (anything more than a few ohms) between terminals 30 and 87 when relay C is closed indicates "bad".

Thanks for the kind words -- I'll have to admit that I know more about TR electrics than I ever wanted to know . I chased one very sneaky Gremlin around my own TR's injection system (a slightly bad ground that was fooling the Lambda system into thinking it was running lean so it would wrongly add extra fuel -- not enough to run bad, but enough so that I couldn't get past the emission test), and I've have had some of the other typical TR electrical problems (burned contacts at the white connectors, dead AC blower power transistor, etc.) so I know the TR wiring diagrams rather well.

 

I've been watching this thread with great interest, some of you may recall that I had major trouble with my 87 Testarossa too. And it was only through Steve's efforts and clear explanations that I was able to solve the problem. Steve.....I am eternally in your debt for all your help. Since getting the ol'e girl running right I haven't let her rest more than 2 days in a row. I've been driving the wheels off and have racked up almost 2k miles in less than 2 months. The car is running terrific and I couldn't be happier. The biggest test of the TR was driving from Michigan down to Indy for the FCA meet. I topped up the tanks and made the whole trip down and back without refueling....at total of 405 miles! The car was on fumes when I rolled back into town. The weather was hot...I hit the rush hour both going and coming back. With temps near 100F the car ran smooth and never missed a beat....in fact the temp gage never got over 205F even in stop-n-go traffic jams. These TRs are great cars once they are all sorted out. I have the utmost confidence that Steve and "a7see" will get through this ordeal.

I didn't mean to chime in and hog up space....but there isn't a better guy to get help from than Steve. Good Luck!

 

Hi Jeff -- That's very kind of you to say, and glad to hear that your TR is running well (and as intended). Al's problem does seem a lot like deja vu all over again after looking at yours (although slightly different root causes).

Al -- Sounds like you've got it surrounded (you can believe the resistance measurements -- were not talking about resolving the difference in milli-ohms here). Glad to help a fellow TRer -- let us know how it works out. (PS -- I'm now thinking that that relay C that you have is the Stribel unit, but I'm NOT going to delve into my "Relays box" to check the markings )

 

Al,

What's the Ferrari part number?